When I get hiccups, I get them bad. I did some googling and found a solution that finally actually worked. I have used this method ever since and it works every time.
Take a huge breath and hold it. While still holding your breath try to take a few more breaths and continue to hold your breath as long as you can. You should notice that your hiccups have stopped and then you can relax and exhale. If not, just repeat the process.
I hope this works for you like it does for me.